A Highly Stretchable Liquid Metal Polymer as Reversible Transitional Insulator and Conductor

Area of Science:

• Materials Science
• Electrical Engineering
• Polymer Science

Background:

• Temperature-controlled reversible electrical transitions are crucial for advanced electronic applications.
• Existing materials are often rigid and difficult to fabricate.
• Developing flexible and easily manufactured transitional insulator and conductor (TIC) materials is a key challenge.

Purpose of the Study:

• To introduce a highly stretchable, temperature-responsive liquid metal polymer composite as a reversible transitional insulator and conductor (TIC).
• To demonstrate its potential for applications requiring flexible and switchable electronic components.

Main Methods:

• Fabrication of a liquid metal polymer composite with high stretchability (680% strain).
• Characterization of its reversible electrical transition between insulator and conductor states triggered by temperature changes.
• Development of a simplified model to predict the behavior of liquid metal droplets during the transition.

Main Results:

• The developed TIC exhibits a resistivity change exceeding 4 × 10^9 times upon temperature tuning within seconds.
• The material transitions from an insulated state to a conductive state upon freezing and recovers upon warming.
• Successful demonstration of a system displaying numbers and letters by converting TIC temperature signals to binary data.

Conclusions:

• The novel liquid metal polymer composite offers a highly stretchable, easily fabricated, and rapidly switchable TIC.
• Its unique properties enable diverse applications including stretchable switches, semiconductors, temperature sensors, and memory devices.
• This work presents a general strategy for creating and utilizing stretchable transitional materials based on liquid metals and polymers.